The subject matter described herein relates generally to methods and systems for wind turbines, and more particularly, to methods and systems concerning the cables inside a wind turbine, even more particularly, the cables routed from the nacelle to the tower.
Energy generated from wind, for example, through the use of large scale wind turbines has experienced rapid growth in recent years. Source of this growth may be the numerous environmental, technical and economic benefits related to wind generated energy production. Wind energy is widely available, renewable and reduces the production of greenhouse gases by diminishing the need of fossil fuels as energy source. Furthermore, improvements in design, manufacturing technologies, materials and power electronic devices of wind turbines has and will in the future continue to decrease production costs of wind turbines while increasing their energy production capabilities and efficiencies.
At least some known wind turbines include a tower and a nacelle mounted on the tower. A rotor is rotatably mounted to the nacelle and is coupled to generator by a shaft. A plurality of blades extend from the rotor. The blades are oriented such that wind passing over the blades turns the rotor and rotates the shaft, thereby driving the generators to generate electricity.
The generators are sometimes, but not always, rotationally coupled to the rotor through a gearbox. The gearbox steps up the inherently low rotational speed of the rotor for the generator to efficiently convert the rotational mechanical energy to electrical energy, which is fed into a utility grid via at least one electrical connection. Gearless direct drive wind turbines also exist. The rotor, generator, gearbox and other components are typically mounted within a housing, or nacelle, that is positioned on top of a base that may be a truss or tubular tower.
In some known wind turbines, the nacelle of a wind turbine contains many power electronic devices that enable a controlled and efficient conversion of wind energy into electrical energy such as, for example, one or more generators, control and cooling systems. The cables of a wind turbine that feed electrical power into electrical supply grids are often routed from the nacelle to the electrical supply grids via the tower.
To maximize the energy production of a wind turbine, the nacelle is typically able to rotate or pivot versus the fix position of the tower. This allows the rotor blades to be in an optimum position with respect to the wind direction. Hence, thereby the wind turbine is able to exploit a maximum amount of wind energy at all times. Equally, to avoid unfavorable wind gusts or extremely high wind speeds the position of the nacelle may be adjusted accordingly. Based on this movement of the nacelle the cables routed from the nacelle to the tower may be pulled together in a kind of knurl, which is not under control. This twisting and curling behavior of the cables during operation of a wind turbine may lead to several issues such as overheating in the knurls or movement of the knurls to other parts in the tower such as, for example, the ladder or lights.
Further, the movement of the knurl may cause excessive wear of the cables or may damage surrounding structures. In the worst case, such uncontrolled movements of the cable knurls may result in entanglement of the cables inside of the tower that may eventually lead to system failure.
For this purpose, it will be appreciated that controlling the cable knurls is desired. Hence, the subject matter described herein pertains to methods and systems that enable the aforementioned control of cable knurls especially, but not limited to the cable knurls formed inside of a wind turbine tower during its operation.